Many mobile devices include a sensor within the housings of the mobile devices to determine when the mobile devices have been exposed to liquids (e.g., to determine when the mobile devices have gotten wet). Such sensors may change colors (e.g., the sensors may change from white to red) when liquids come into contact with the sensors. Such color changes alert service providers when liquids have breached housings of the mobile devices, thus affecting whether device warranties for the mobile devices are still valid.